Trim any silver skin and excess fat from the pork, then cut the meat into 1-inch pieces. Season with the salt.

Heat 1 tablespoon of the oil in a large skillet over medium-high heat. Once the oil shimmers, add half of the pork. Sear for a few minutes, undisturbed, until browned on one side, then stir to brown on at least one other side of each piece. Transfer to a plate; it will not be cooked through. Add the remaining pork and cook in the same way, collecting all of the pork on the plate.

Meanwhile, cut the eggplant into ½-inch pieces. Cut the onion in half, then into very thin half-moons. Cut the bell pepper into thin strips, discarding the seeds and ribs.

Add the remaining 2 tablespoons of oil to the skillet; use a wooden spoon to dislodge any browned bits. Once the oil shimmers, add the eggplant, onion and bell pepper. Stir-fry for 3 minutes, then add 2 tablespoons of the Sriracha and all of the water. Cook for 1 minute, then return the pork and any accumulated juices to the skillet. Reduce the heat to medium-low; cover partially and cook for 8 minutes or just long enough for the pork to be cooked through yet remain tender. The vegetables should be slightly softened.

Taste, and add the remaining Sriracha, if desired. Remove from the heat.